/* <!-- copyright */
/*
 * aria2 - The high speed download utility
 *
 * Copyright (C) 2010 Tatsuhiro Tsujikawa
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 *
 * In addition, as a special exception, the copyright holders give
 * permission to link the code of portions of this program with the
 * OpenSSL library under certain conditions as described in each
 * individual source file, and distribute linked combinations
 * including the two.
 * You must obey the GNU General Public License in all respects
 * for all of the code used other than OpenSSL.  If you modify
 * file(s) with this exception, you may extend this exception to your
 * version of the file(s), but you are not obligated to do so.  If you
 * do not wish to do so, delete this exception statement from your
 * version.  If you delete this exception statement from all source
 * files in the program, then also delete it here.
 */
/* copyright --> */
#include "AdaptiveFileAllocationIterator.h"
#include "BinaryStream.h"
#ifdef HAVE_FALLOCATE
# include "FallocFileAllocationIterator.h"
#endif // HAVE_FALLOCATE
#include "SingleFileAllocationIterator.h"
#include "RecoverableException.h"
#include "LogFactory.h"
#include "Logger.h"

namespace aria2 {

AdaptiveFileAllocationIterator::AdaptiveFileAllocationIterator
(BinaryStream* stream, off_t offset, uint64_t totalLength):
  stream_(stream), offset_(offset), totalLength_(totalLength),
  logger_(LogFactory::getInstance()) {}

AdaptiveFileAllocationIterator::~AdaptiveFileAllocationIterator() {}

void AdaptiveFileAllocationIterator::allocateChunk()
{
  if(allocator_.isNull()) {
#ifdef HAVE_FALLOCATE
    try {
      if(logger_->debug()) {
        logger_->debug("Testing file system supports fallocate.");
      }
      if(static_cast<uint64_t>(offset_) < totalLength_) {
        off_t len = std::min(totalLength_-offset_, static_cast<uint64_t>(4096));
        stream_->allocate(offset_, len);
        offset_ += len;
      }
      if(logger_->debug()) {
        logger_->debug("File system supports fallocate.");
      }
      allocator_.reset
        (new FallocFileAllocationIterator(stream_, offset_, totalLength_));
    } catch(RecoverableException& e) {
      if(logger_->debug()) {
        logger_->debug("File system does not support fallocate.");
      }
      SharedHandle<SingleFileAllocationIterator> salloc
        (new SingleFileAllocationIterator(stream_, offset_, totalLength_));
      salloc->init();
      allocator_ = salloc;
    }
#else // !HAVE_FALLOCATE
    SharedHandle<SingleFileAllocationIterator> salloc
      (new SingleFileAllocationIterator(stream_, offset_, totalLength_));
    salloc->init();
    allocator_ = salloc;
#endif // !HAVE_FALLOCATE
    allocator_->allocateChunk();
  } else {
    allocator_->allocateChunk();
  }
}
  
bool AdaptiveFileAllocationIterator::finished()
{
  if(allocator_.isNull()) {
    return (uint64_t)offset_ >= totalLength_;
  } else {
    return allocator_->finished();
  }
}

} // namespace aria2
